Every series usually has its very own unusual/gimmicky blaster. For the original Vortex Series, that blaster was the Powerstrike:
The Powerstrike was released in 1999 and is unusual in two ways. First, it utilizes a dual action firing system, which was unique to it. Second, it was made to fire two rings off of each launcher. The Powerstrike originally came with two Spinfire rings and two Micro Spinfire rings which would be loaded, one of each on to each launcher. The Powerstrike also could fire each launcher separately or in tandem, allowing it achieve a shotgun like effect.
Despite being very strangely shaped, the Powerstrike is a very comfortable and usable blaster. It's not the most well known of the Vortex series, but I'd say that it's one of coolest.